Moretown, Vermont Phase 2 Stream Geomorphic Assessment & River Corridor Plan

Transcription

1 Moretown, Vermont Phase 2 Stream Geomorphic Assessment & River Corridor Plan D R AF T January 31, 2018 Prepared by: 149 State Street, Suite 3 Montpelier, Vermont Prepared under contract to: Central Vermont Regional Planning Commission 29 Main Street, Suite 4 Montpelier, VT Funding for this project was provided by: State of Vermont Ecosystem Restoration Program

2 Moretown, Vermont Phase 2 Stream Geomorphic Assessment & River Corridor Plan TABLE OF CONTENTS 1.0 EXECUTIVE SUMMARY LOCAL PLANNING PROGRAM OVERVIEW OVERVIEW RIVER CORRIDOR PLANNING TEAM LOCAL PROJECT OBJECTIVES GOALS OF THE VERMONT RIVER MANAGEMENT PROGRAM BACKGROUND WATERSHED INFORMATION WATERSHED DESCRIPTION GEOMORPHIC SETTING HYDROLOGY METHODS PHASE 1 METHODOLOGY PHASE 2 METHODOLOGY BRIDGE AND CULVERT METHODOLOGY CONDITION AND DEPARTURE ANALYSIS Stream Types Geomorphic Condition Habitat Condition Sediment Regime Channel Evolution Model RESULTS REACH/SEGMENT DESCRIPTIONS STREAM CROSSINGS PRELIMINARY PROJECT IDENTIFICATION PROJECT IDENTIFICATION PROGRAM DESCRIPTIONS NEXT STEPS LIST OF ACRONYMS AND GLOSSARY OF TERMS REFERENCES Appendix A Maps Appendix B Bridge & Culvert Assessment Data Appendix C Potential Project Locations & Descriptions Appendices

3 Moretown, Vermont Phase 2 Stream Geomorphic Assessment & River Corridor Plan 1.0 EXECUTIVE SUMMARY A stream geomorphic assessment within the Mad River and middle Winooski River watersheds was conducted by (BCE) under the direction of Central Vermont Regional Planning Commission () and the Vermont Agency of Natural Resources (VANR) during the summer and fall of Funding for the project was provided through the State of Vermont Ecosystem Restoration Program. A planning strategy based on fluvial geomorphic science (see glossary at end of report for associated definitions) was chosen because it provides a holistic, watershed scale approach to identifying the stressors on river ecosystem health. The stream geomorphic assessment data can be used by resource managers, community watershed groups, municipalities and others to identify how changes to land use alter the physical processes and habitat of rivers. The town of Moretown, Vermont experienced major flooding in August 2011 and subsequent damage to infrastructure as a result of Tropical Storm Irene (TSI). As part of the long term plan to mitigate the impact of flooding, improve aquatic habitat, and increase river stability, Central Vermont Regional Planning Commission secured state funding to complete a Phase 2 stream geomorphic assessment for several streams within the town. The stream geomorphic assessment data will be used to help focus stream restoration and protection activities within the watershed and assist town with flood resiliency planning. The study encompassed approximately 11 miles of stream channel within 13 reaches on the Mad River, Welder Brook, Dowsville Brook, Jones Brook, Kelley Brook, and Herring Brook. This stream geomorphic assessment facilitated the identification of major stressors to geomorphic stability and habitat conditions within the study area. The predominant stressor observed for these streams is stream channel straightening and corridor encroachment associated with the existence of roads and development. In many cases, this encroachment has limited floodplain access and has caused moderate to extreme channel degradation (lowering of the bed) resulting in sediment build up, channel widening, and planform adjustment (lateral movement). Numerous state and town highways were historically built into river valleys throughout the study area, including critical travel routes such as Vermont Routes 100 and 100B. The village of Moretown, a hub of residential and municipal activity, lies within the Mad River Valley. Following Tropical Storm Irene, immense recovery efforts were undertaken to repair roads, buildings, and other infrastructure that were damaged by the flooding. Moving forward, it is important for communities to continually prepare for the next flood by taking steps to become

4 Moretown, Vermont Phase 2 SGA & River Corridor Plan Page 2 more flood resilient. This report outlines strategies that can be implemented on both sitespecific and community wide levels to mitigate flood damage and losses in the future. The river corridor planning effort in Moretown is a continuous and collaborative process. The stream geomorphic assessment data collected in this study build on other data that have been collected throughout the Mad River and Winooski River watersheds in the past decade. Analysis of these data has aided the identification of major impacts and stressors and the development of projects to mitigate impacts, increase geomorphic stability, and improve aquatic habitat. A list of 43 potential restoration, conservation, and flood resiliency projects was developed using the stream geomorphic assessment data collected within the study area. The projects fall within five categories, as outlined by the Vermont Watershed Management Division in its Watershed Projects Database table: Project Category Number of Proposed Projects Agricultural Pollution Prevention Preliminary Design 2 Dam Removal Preliminary Design 1 Floodplain/Stream Restoration Preliminary Design 17 River Planting 17 River Corridor Easement Design 6 Total Number of Projects 43 Types of projects include river corridor easements, riparian buffer improvements, berm removals, bridge and culvert replacements, dam removal, and more. Potential projects will be prioritized based on several factors, including ease of implementation, cost, landowner interest, effectiveness, and site specific factors. Further project development, including additional data collection, may be required for project design, permitting, and implementation.

5 Moretown, Vermont Phase 2 SGA & River Corridor Plan Page LOCAL PLANNING PROGRAM OVERVIEW There are many scientific terms used in this river corridor plan, and the reader is encouraged to refer to the glossary at the end of the document. Important terms that are in the glossary are shown in italics the first time they are used in the text. 2.1 Overview This project focuses on the Winooski River watershed in the town of Moretown, Vermont, although small sections of Duxbury and Berlin are also included. The study area is comprised of two watersheds that drain to the Winooski River the Mad River watershed and the Jones Brook watershed. The Mad River and several of its tributaries, as well as Jones Brook and two of its tributaries, were assessed during the summer and fall of 2017 using the Vermont Agency of Natural Resources Phase 2 Stream Geomorphic Assessment protocol. Mad River tributaries included in this assessment are Welder Brook, Doctors Brook, and Dowsville Brook. Jones Brook tributaries that underwent assessment are Kelley Brook and Herring Brook. Phase 2 geomorphic assessments have occurred in numerous areas in the Winooski River watershed within the past decade. Corridor plans for other phase 2 assessment areas in the Winooski River watershed can be found at The Vermont Rivers Program has developed state of the art Stream Geomorphic Assessment (SGA) protocols that utilize the science of fluvial geomorphology (fluvial = water, geo = earth, and morphology = the study of structure or form). Fluvial geomorphology focuses on the processes and pressures operating on river systems. The Vermont protocol includes three phases: 1. Phase 1 Remote sensing and cursory field assessment; 2. Phase 2 Rapid habitat and rapid geomorphic assessments to provide field data to characterize the current physical condition of a river; and 3. Phase 3 Detailed survey information for designing active channel management projects. 2.2 River Corridor Planning Team The river corridor planning team for this stream geomorphic assessment is comprised of Central Vermont Regional Planning Commission (), Bear Creek Environmental (BCE), the Vermont Agency of Natural Resources (VANR), the Town of Moretown, the Friends of the Mad River, and the Friends of the Winooski River. The 2017 study was funded through The State of Vermont Ecosystem Restoration Program under contract to Central Vermont Regional Planning Commission. Gretchen Alexander from the Vermont River Management Program of VANR provided a quality control/assurance review of the stream geomorphic assessment data, as well

6 Moretown, Vermont Phase 2 SGA & River Corridor Plan Page 4 as assistance with field work, and the Central Vermont Regional Planning Commission assisted with the field work and provided the overall project coordination. 2.3 Local Project Objectives The stream geomorphic assessment data are useful to resource managers, community watershed groups, municipalities and others for identifying how changes to land use alter the physical processes and habitat of rivers. Characterizing stream type, identifying stressors in the watershed, and assessing the health of aquatic habitat and the riparian corridor are essential for the preparation of an effective and long term river corridor plan. Central Vermont Regional Planning Commission and project partners, in collaboration with towns and other organizations, have the opportunity to address and mitigate major watershed stressors through the design and implementation of restoration and protection projects outlined in this corridor plan. The Water Quality Management Plan (WQMP) for Basin 8 (Winooski River) outlines several strategies to restore and protect all surface waters within the Winooski River watershed. Goals in the Winooski River basin include improving water quality, protecting habitat, and reducing river development conflicts. There are numerous reaches within the Winooski River watershed that have impaired water quality. Specific to the study area, the basin plan identifies that bacterial contamination is an issue on the Mad River from the mouth to Moretown (Vermont Agency of Natural Resources, 2012b). 2.4 Goals of the Vermont River Management Program The State of Vermont s Rivers Program has set out several goals and objectives that are supportive of the local initiative in Moretown. The state management goal is to, manage toward, protect, and restore the fluvial geomorphic equilibrium condition of Vermont rivers by resolving conflicts between human investments and river dynamics in the most economically and ecologically sustainable manner (Vermont Agency of Natural Resources, 2009b). The objectives of the Program include fluvial erosion hazard mitigation and sediment and nutrient load reduction, as well as aquatic and riparian habitat protection and restoration. The Program seeks to conduct river corridor planning in an effort to remediate the geomorphic instability that is largely responsible for problems in a majority of Vermont s rivers. Additionally, the Vermont River Management Program has set out to provide funding and technical assistance to facilitate an understanding of river instability and the establishment of well developed and appropriately scaled strategies to protect and restore river equilibrium. 3.0 BACKGROUND WATERSHED INFORMATION 3.1 Watershed Description The Winooski River begins in Cabot, Vermont and flows for approximately 90 miles before entering Lake Champlain in Colchester, Vermont. The Mad River is a 28 mile long river that drains roughly 144 square miles. It begins in the town of Granville and flows north through

7 Moretown, Vermont Phase 2 SGA & River Corridor Plan Page 5 Warren, Waitsfield, and Moretown, where it meets the Winooski River. Jones Brook is a smaller tributary to the Winooski River with a watershed size of only 10 square miles. It originates in Moretown and flows through Berlin where it meets the Winooski River 4.5 river miles later (VANR, 2017). The Mad River and Jones Brook watersheds are located in the Northern Green Mountain biophysical region. This region is characterized by Thompson and Sorenson (2000) as an area of high elevations, which includes Vermont s tallest peaks. These mountains greatly influence the climate of the region. Precipitation is abundant in this region, and temperatures are colder than in other areas due to higher elevations. The typical zonation of forest types can be found in this biophysical region. From the lower slopes to the summits, Northern Hardwood Forest change to Montane Yellow Birch Red Spruce Forest, to Montane Spruce Fir Forest, and finally to Subalpine Krummholz at the tree lines (Thompson and Sorenson, 2000). The Northern Green Mountains contain extensive habitat for mammals such as bear, white tailed deer, bobcat, fisher, beaver, and red squirrel. Bird species that nest in high elevations include blackpoll warblers, Swainson s thrush, and the rare Bicknells thrush (Thompson and Sorenson, 2000). 3.2 Geomorphic Setting A Phase 1 Stream Geomorphic Assessment of the Mid Winooski River watershed (which contains the Jones Brook watershed) was completed in 2007 by Bear Creek Environmental. During Phase 1, the Mid Winooski River watershed was broken into 129 reaches; each reach represents a similar section of the stream based on physical attributes such as valley confinement, slope, sinuosity, bed material, dominant bedform, land use, and other hydrologic characteristics. The Phase 1 assessment for the Mad River watershed was completed in 2007 by Field Geology Services. This assessment created 116 reaches throughout the watershed. A total of 13 reaches were included in this Phase 2 assessment, which equates to just over 11 river miles (see Figure 3.1). Each point in Figure 3.1 represents the downstream end of the reach.

8 D R AF T Moretown, Vermont Phase 2 SGA & River Corridor Plan Figure 3.1. Mad River and Jones Brook watershed 2017 Phase 2 study reaches. Page 6

9 Moretown, Vermont Phase 2 SGA & River Corridor Plan Page Hydrology In late August of 2011, Vermont was hit hard by Tropical Storm Irene (TSI). Heavy rain totaled over seven inches in areas over the course of one day. This immense downpour caused raging floodwaters to tear through Vermont s streams, devastating people and infrastructure throughout central and southern Vermont. In some areas, TSI flooding approached historic flood levels, while in other areas, the storm greatly exceeded them. Over 500 miles of state roads, in addition to over 2000 segments of municipal roads, were damaged as a result of TSI. In total, approximately 500 bridges were damaged or destroyed, as well as almost 1,000 culverts. Approximately 1,500 residences were significantly damaged or destroyed as a result of flooding, as well as state, municipal, and commercial buildings (VANR 2012a). The Winooski River and tributaries (including the Mad River) were impacted by flooding from Tropical Storm Irene, as were the communities located on their floodplains. Within the Phase 2 study area, Tropical Storm Irene was the most damaging storm since the Flood of During Tropical Storm Irene, flood levels throughout many areas in Vermont equaled or approached the historic flood of 1927 (Vermont Agency of Natural Resources, 2012a). Many towns along the Winooski River and the Mad River experienced significant flooding and damage of property and infrastructure. Moretown was particularly hard hit, especially in its village, where development is most dense along the Mad River. Numerous homes, as well as municipal buildings, were majorly damaged by flooding during Irene. According to the Central Vermont Regional Planning Commission, the flood waters in Moretown Village rose to the ceiling of many first floor homes and flooded the Moretown Town Office destroying nearly all Town records. Additionally, undersized culverts throughout the town sustained damage and/or washed out entirely during Irene. Road damage was widespread. In order to better understand the flood history of the Winooski River, the Mad River, and their tributaries, long term data from the U.S. Department of the Interior, U.S. Geological Survey (USGS), were obtained (USGS, 2017). Peak flow data from two gaging stations at nearby locations in the Winooski River watershed were reviewed. One station included in this analysis has a drainage area of 139 square miles and is located on the Mad River in Moretown. A second station, located on the Winooski River main stem in Montpelier (drainage area 397 square miles), was included in this analysis. Comparing annual peak flow data at these two stations for all years on record allows for an analysis of the recurrence interval of Tropical Storm Irene within the watershed. Peak discharge records are available for the Mad River near Moretown, Vermont from 1928 through 2016 (Figure 3.2) (USGS, 2017). The highest annual peak flow on record is from Tropical Storm Irene in August 2011, which exceeded a 100 year recurrence interval. The peak flow of 24,200 cubic feet per second (cfs) on August 28, 2011 was slightly higher than the peak flow of 23,000 cfs reported for the 1927 flood.

10 Moretown, Vermont Phase 2 SGA & River Corridor Plan Page 8 At the Winooski River gaging station, peak discharge records are available from 1912 through The highest peak discharge available over the period of record for this station is from the Flood of 1927, which caused immense damage in central Vermont. Following the Flood of 1927, several flood control dams were installed in the Winooski River watershed. The Wrightsville Reservoir Dam on the North Branch of the Winooski River was completed in late 1935 and is located a short distance from the gaging station. The installation of this dam and another flood control dam farther upstream in East Barre has regulated the flows on the Winooski River. This regulation has resulted in lower peak flows at the gaging station in Montpelier due to increased floodwater storage capacity (Figure 3.3). Of all the natural hazards experienced in Vermont, flooding is the most frequent, damaging, and costly. During the period of alone, flood losses in Vermont totaled nearly $57 Million (Vermont Agency of Natural Resources, 2010b). The Vermont Agency of Administration (2012) states that over 733 million dollars has been estimated in funding resources for Tropical Storm Irene recovery. While some flood losses are caused by inundation (i.e. waters rise, fill, and damage low lying structures), most flood losses in Vermont are caused by fluvial erosion. Fluvial erosion is caused by rivers and streams, and can range from gradual bank erosion to catastrophic changes in river channel location and dimension during flood events The VANR attributes the high cost and frequency of fluvial erosion in Vermont to its geography (mountainous setting with narrow valleys and extreme climate) and past land use practices (forest clearing) (VANR, 2010b).

11 Moretown, Vermont Phase 2 SGA & River Corridor Plan Page Annual Peak Flows Mad River near Moretown, VT USGS Annual Peaks 10 yr. discharge 25 yr. discharge 50 yr. discharge 100 yr. discharge Discharge (cfs) Flood of Figure 3.2. Annual Peak Flows for the Mad River near Moretown, Vermont Water Year *Discharges for annual exceedance probabilities from USGS report "Annual Exceedance Probabilities of Peak Discharges of 2011 at Streamgages in Vermont and Selected Streamgages in New Hampshire, Western Massachusetts, and Northeastern New York" (2013). Discharge (cfs) Annual Peak Flows Winooski River at Montpelier, VT USGS Flood of 1927 Tropical StormIrene Annual Peaks 10 yr. discharge 25 yr. discharge 50 yr. discharge 100 yr. discharge 500 yr. discharge* Data from 1912 to 1935 represent peak flows with an unknown degree of regulation due to the presence of small dams upstream in the watershed. Construc tion of the Wrightsville Reservoir Dam (a large flood control dam) on the North Branch of the Winooski River was completed in late From 1936 onward, peak flow data on the Winooski River at Montpelier have been affected by regulation at the Wrightsville Reservoir Dam Water Year *Discharges for annual exceedance probabilities from USGS report "Annual Exceedance Probabilities of Peak Discharges of 2011 at Streamgages in Vermont and Selected Streamgages in New Hampshire, Western Massachusetts, and Northeastern New York" (2013). Figure 3.3. Annual Peak Flows for the Winooski River at Montpelier, Vermont.

12 Moretown, Vermont Phase 2 SGA & River Corridor Plan Page METHODS A summary of the Phase 1, Phase 2, and Bridge and Culvert methodologies is provided in the following sections. 4.1 Phase 1 Methodology The Phase 1 assessment followed procedures specified in the Vermont Stream Geomorphic Assessment Phase 1 Handbook (Vermont Agency of Natural Resources), and used the Stream Geomorphic Assessment Tool (SGAT). SGAT is an ArcGIS extension. Phase 1, the remote sensing phase, involves the collection of data from topographic maps and aerial photographs, from existing studies, and from very limited field studies, called windshield surveys. The Phase 1 assessment provides an overview of the general physical nature of the watershed. As part of the Phase 1 study, stream reaches are determined based on geomorphic characteristics such as: valley confinement, valley slope, geologic materials, and tributary influence. 4.2 Phase 2 Methodology The Phase 2 assessment in Moretown followed procedures specified in the Vermont Stream Geomorphic Assessment (SGA) Phase 2 Handbook (VANR, 2009b), and used version of the SGAT Geographic Information System (GIS) extension to index impacts within each reach. The geomorphic condition for each Phase 2 reach is determined using the Rapid Geomorphic Assessment (RGA) protocol, and is based on the degree of departure of the channel from its reference stream type (VANR, 2009b). The study used the 2008 Rapid Habitat Assessment (RHA) protocol (VANR, 2008; Milone and MacBroom, Inc., 2008). The RHA is used to evaluate the physical components of a stream (channel bed, banks, and riparian vegetation) and how the physical condition of the stream affects aquatic life. The RHA results can be used to compare physical habitat condition between sites, streams, or watersheds, and they can also serve as a management tool in watershed planning. RHA and RGA field forms were completed for the Phase 2 reaches. The appropriate RHA and RGA forms were selected based on segment characteristics and scored according to the data collected from the field assessment. A segment score and corresponding condition were determined for both the RHA and the RGA. Additionally for the RGA, major geomorphic processes were identified, the stage of channel evolution was determined, and a stream sensitivity rating was assigned. To assure a high level of confidence in the Phase 2 SGA data, strict quality assurance/quality control (QA/QC) procedures were followed by Bear Creek Environmental. These procedures involved a thorough in house data review, which took place during the fall and winter of The Project Team conducted the assessment according to the approved Quality Assurance procedures specified in the Phase 2 handbook. Gretchen Alexander of the State of Vermont

13 Moretown, Vermont Phase 2 SGA & River Corridor Plan Page 11 Watershed Management Division conducted a QA/QC review of the data collected by (BCE) for the project during January Bridge and Culvert Methodology Bridge assessments were conducted by BCE on all public and private crossings within the selected Phase 2 reaches. The Agency of Natural Resources Bridge and Culvert protocols (VANR, 2009a) were followed. Latitude and Longitude at each of the structures was determined using an AshTech MobileMapper 100 GPS unit. The assessment included photo documentation of the inlet, outlet, upstream, and downstream of each of the structures. The Vermont Culvert Geomorphic Compatibility Screening Tool (Milone and MacBroom, Inc. 2008) was used to determine geomorphic compatibility for each bridge. Bridges are not typically screened for geomorphic compatibility in the VANR protocol because they are usually more robust and have less impact on stream channel function than culverts. Bridges also do not have potential to become perched above the water surface, because the bottom of the structure is natural substrate. Bridges in this study were screened using the geomorphic compatibility tool that was modified to exclude the slope parameter. Tables 1 and 2 in Appendix B explain how each bridge was scored using the Screening Tool. The compatibility rating is based on four criteria: structure width in relation to bankfull channel width, sediment continuity, river approach angle, and erosion & armoring and the ratings span the following range: Fully Compatible Mostly Compatible Partially Compatible Mostly incompatible Fully Incompatible All culverts were evaluated for Aquatic Organism Passage (AOP) using the Vermont Culvert Aquatic Organism Passage Screening Tool (Milone and MacBroom, Inc., 2009). Tables 3 through 5 in Appendix B explain how each culvert was scored. The screening guide has the four following categories: Full AOP for all organisms Reduced AOP for all aquatic organisms No AOP for all aquatic organisms except adult salmonids No AOP for all aquatic organisms

14 Moretown, Vermont Phase 2 SGA & River Corridor Plan Page Condition and Departure Analysis Stream Types Reference stream types are based on the valley type, geology and climate of a region and describe what the channel would look like in the absence of human related changes to the channel, floodplain, valley width, and/or watershed. Table 1 shows the typical characteristics used to determine reference stream types (VANR, 2009b). Reference reach typing was based on both the Rosgen (1996) and the Montgomery and Buffington (1997) classification systems. Table 1. Reference Stream Type Stream Type Confinement Valley Slope Bed Form A Narrowly Confined Very steep > 6.5 % Cascade A Confined Very steep % Step Pool B B C or E D F Confined or Semi confined Confined, Semi confined or Narrow Unconfined (Narrow, Broad or Very Broad) Unconfined (Narrow, Broad or Very Broad) Confined or Semi confined Steep % Moderate to Steep % Moderate to Gentle <2.0 % Moderate to Gentle <4.0 % Moderate to Gentle <4.0 % Step Pool Plane Bed Riffle Pool or Dune Ripple Braided Channel Variable During the Phase 2 assessment, the 13 study reaches were broken into 29 segments based on detailed field observations. A segment is distinct in one or more of the following parameters: degree of floodplain encroachment or channel alteration, grade control occurrence (e.g. ledge), channel dimensions, channel sinuosity and slope, riparian buffer and corridor conditions, and degree of flow regulation. The most downstream segment within a reach is labeled A, the second from the reach point is B, etc. (i.e. M09 A is the most downstream segment on Reach M09). The existing stream type is based on channel dimensions measured during the Phase 2 assessment. A stream type departure occurs when the channel dimensions deviate so far from the reference condition that the existing stream type is no longer the reference stream type. These stream type departures represent a significant change in floodplain access and stability. Watersheds that have lost attenuation or sediment storage areas due to human related constraints are generally more sensitive to erosion hazards, transport greater quantities of sediment and nutrients to receiving waters, and lack the sediment storage and distribution processes that create and maintain habitat (VANR, 2009b).

15 Moretown, Vermont Phase 2 SGA & River Corridor Plan Page Geomorphic Condition The stream condition is determined using the scores on the rapid assessment field forms, and is defined in terms of departure from the reference condition. There are four categories to describe the condition (reference, good, fair and poor). These ratings are defined below. Reference no departure Good minor departure Fair major departure Poor severe departure Geomorphic condition is determined based on the degree (if any) of channel degradation, aggradation, widening and planform adjustment. Degradation is the term used to describe the process whereby the stream bed lowers in elevation through erosion, or scour, of bed material. Aggradation is a term used to describe the raising of the bed elevation through an accumulation of sediment. The planform of a channel is its shape as seen from the air. Planform change can be the result of a straightened course imposed on the river through different channel management activities, or a channel response to other adjustment processes such as aggradation and widening. Channel widening is a result of channel degradation or sediment build up in the channel. In both situations the stream s energy is concentrated into both banks Habitat Condition A second condition rating is used to evaluate reaches in a phase 2 assessment habitat condition. Habitat condition is determined using the scores on the rapid habitat assessment (RHA) field forms. The categories for condition rating are the same as those detailed above for geomorphic condition. Scores assigned for the RHA are based on parameters that evaluate the physical characteristics of a stream. This method relates these characteristics to the habitat they provide for aquatic organisms. The RHA evaluates such characteristics as woody debris content, deposition and scour features, channel morphology, and bank and buffer vegetation Sediment Regime Functioning floodplains play a crucial role in providing long term stability to a river system. Natural and anthropogenic impacts may alter the equilibrium of sediment and discharge in natural stream systems and set in motion a series of morphological responses (aggradation, degradation, widening, and/or planform adjustment) as the channel tries to reestablish a dynamic equilibrium. Small to moderate changes in slope, discharge, and/or sediment supply can alter the size of transported sediment as well as the geometry of the channel; while large changes can transform reach level channel types (Ryan, 2001). Human induced practices that have contributed to stream instability in the Mad River and Jones Brook watersheds include: Channelization and bank armoring Removal of woody riparian vegetation Floodplain encroachments

16 Moretown, Vermont Phase 2 SGA & River Corridor Plan Page 14 These anthropogenic practices have altered the balance between water and sediment discharges within the Mad River and Jones Brook watersheds. The sediment regime is the quantity, size, transport, sorting, and distribution of sediments. The sediment regime may be influenced by the proximity of sediment sources, the hydrologic characteristics of the region, and the valley, floodplain, and stream morphology (VANR, 2010a). Sediment can be supplied to the river through bank erosion, large flooding events, and stormwater inputs. Reference and existing sediment regimes were derived from the Agency of Natural Resources Data Management System according to the sediment regime criteria established by the Vermont Agency of Natural Resources (2010a). Changes in hydrology (such as flow alteration and development of land within the riparian corridor) as well as sediment storage within the watershed have altered the reference sediment regime types for many segments within the study area. The analysis of sediment regimes at the watershed level is useful for summarizing the stressors affecting geomorphic condition of river channels. Sediment regime mapping provides a context for understanding the sediment transport and channel evolution processes Channel Evolution Model Channel morphologic responses to anthropogenic practices contribute to channel adjustment that may further create unstable channels. All three adjustment processes, aggradation, widening and planform migration as a result of active and historic channel management are present within the Mad River and Jones Brook watersheds in the Moretown study area. The placement of state highways and town road has significantly changed river valley widths, reduced floodplain access, and altered ability of streams to meander within the study area. The floods that came through the area during TSI in August, 2011 have resulted in aggradation and planform change within some reaches. The segment condition ratings indicate that most of the segments are actively undergoing or have historically undergone a process of major geomorphic adjustment. Many of the reaches studied in the Moretown area are undergoing a channel evolution process in response to human influences on the watershed. The F stage channel evolution model (VANR, 2009b; VANR, 2004) is helpful for explaining the channel adjustment processes underway in the Mad River and Jones Brook watersheds, and is used to understand the process that occurs when a stream degrades (incises). The common stages of the F channel evolution stage, as depicted in Figure 4.1 include:

17 Moretown, Vermont Phase 2 SGA & River Corridor Plan Page 15 Stable (F 1) a pre disturbance period Incision (F II) channel degradation (headcutting) Widening (F III) bank failure Stabilizing (F IV) channel narrows through sediment build up and moves laterally building juvenile floodplain Stable (F V) gradual formation of a stable channel with access to its floodplain at a lower elevation Figure 4.1 Typical channel evolution models for F Stage (VANR, 2009b) When stream channels are altered through straightening, it can set this evolution process into motion and cause adjustment processes to occur. The bed erosion that occurs when a meandering river is straightened in its valley is a problem that translates to other sections of the stream. Localized incision will travel upstream and into tributaries, thereby eroding sediments from otherwise stable streambeds. These bed sediments will move into and clog reaches downstream, leading to lateral scour and erosion of the stream banks. Channel evolution processes may take decades to play out. Even landowners that have maintained wooded areas along their stream and riverbanks may have experienced eroding banks as stream channel slopes adjust to match the valley slopes. It is difficult for streams to attain a new equilibrium where the placement of roads and other infrastructure has resulted in little or no valley space for the stream to access or to create a floodplain. A second channel evolution model, known as the D channel evolution model is helpful for explaining channel adjustments that are driven by major aggradation. In the D model, channel degradation has not occurred, but rather the accumulation of sediment on the streambed causes channel widening and planform adjustment. 5.0 RESULTS The results of the Phase 2 study in Moretown are described by reach and segment in section 5.1 below. Maps in Appendix A show the results for geomorphic condition, habitat condition, and sediment regime for each segment that was assessed. Of the 29 segments, 1 was found to be in reference geomorphic condition, 7 were in good geomorphic condition, 17 were in fair geomorphic condition, 2 were in poor geomorphic condition, and 2 were not evaluated

18 Moretown, Vermont Phase 2 SGA & River Corridor Plan Page 16 for geomorphic condition due to not being fully assessed. The segments were not fully assessed because one is a bedrock gorge and the other was impounded by a dam at the time the field work was completed. The current geomorphic condition ratings in the assessed segments are a result of several factors. Corridor encroachments are common throughout the study area, as many roads run directly along these streams and houses exist on their banks. Development within a river corridor can cause a loss of floodplain access, changes in valley confinement, and overall geomorphic instability. Historic channel straightening is prevalent on the streams included in this assessment and has led to adjustments that are reflected in geomorphic condition scores. During Tropical Storm Irene, high stream flows likely caused changes within the study reaches. Mass failures, erosion, and aggradation were exacerbated by TSI in some locations, and are contributing to the unstable geomorphic condition of many assessment reaches. Also, new flood chutes likely formed, and some sections of stream took new courses through channel avulsions. The rapid habitat assessment resulted in 8 segments in good habitat condition, 19 in fair habitat condition, and 2 not assessed for habitat condition. The segments that are in good habitat condition generally have a more natural channel planform and features such as well vegetated banks and buffers, abundant in channel large woody debris, and a diversity of bed features including many pools, all of which provide habitat for aquatic life. Segments in fair habitat condition have fewer of these features and characteristics and thus provide less habitat for aquatic organisms. As shown on the maps on pages 3 and 4 of Appendix A, many segments have experienced a departure from their reference sediment regime. Eight of 29 segments have existing sediment regimes that match their reference sediment regime; 19 segments have undergone a departure in their sediment regime, and two were not evaluated. Additionally, channel evolution stage for each Phase 2 segment was determined based on field data and observations. This information is provided by segment in section 5.1 below. 5.1 Reach/Segment Descriptions A description of each segment is provided in this section, including major stressors and evolution processes. The segments are listed by stream location from downstream to upstream in the watershed and on each stream. Phase 2 Segment Summary Reports from the Agency of Natural Resources Data Management System, which contain all the data for the Phase 2 steps, can be found at the following link: Site specific projects have been developed to facilitate restoration, conservation, and increased flood resiliency within the study watersheds. Proposed project locations are provided on maps in Appendix C. Tables and photos provide greater detail about proposed projects in Appendix C. The Phase 2 stream geomorphic assessment provides a picture of the condition of the channel and the adjustment process occurring; however, it is not a comprehensive study for determining site specific actions. The Phase 2 study provides a foundation for project development, and additional work is recommended to further develop these projects.

19 Moretown, Vermont Phase 2 SGA & River Corridor Plan Page 17 Mad River M03 Reach 3 on the Mad River begins at the downstream end at the Moretown No. 8 hydroelectric dam and continues upstream to Kenneth Ward Park. The reach is nearly 3,500 feet in length and the river flows along Vermont Route 100B. This reach was not segmented during the assessment. The Mad River in reach M03 is backwatered due to the presence of Moretown Dam No. 8 immediately downstream. For this reason, a full Phase 2 assessment could not be completed for M03. The river flows through a semi confined valley in this reach. Impacts include a lacking riparian buffer due to the presence of RT 100B and stormwater inputs from the road. Bank armoring is present in some areas along RT 100B. Invasive Japanese knotweed is prevalent on both banks within this reach. Figure 5.1. M03 looking downstream impounded. 1 N/A Not Applicable M03 Data Summary *NOT ASSESSED Reference Existing Confinement Semi Confined Semi Confined Length: 3,486 ft Stream Type B C B C Drainage Area: 142 sq. mi. Entrenchment Ratio N/A Evolution Stage: N/A 1 Incision Ratio < 1.2 N/A Sensitivity: N/A Dominant Bed Material Gravel Gravel Dominant Bedform Riffle Pool Riffle Pool Major Stressors: Impoundment from dam downstream, lacking buffer, stormwater inputs

20 Moretown, Vermont Phase 2 SGA & River Corridor Plan Page 18 M04 Reach 4 on the Mad River starts downstream at Kenneth Ward Park and continues upstream to just below the bridge on Bridge Road in Moretown. The river flows along VT 100B, Spillway Road, as well as farms, houses, and forest for just over 9,000 feet. The river valley within M04 is semi confined. This reach was not segmented during the Phase 2 assessment. The majority of the reach appears to have been historically straightened due to the presence of Route 100B and adjacent residential and agricultural land uses. This straightening led to minor historic incision; widening is possibly being prevented by bank armoring. Additional impacts in M04 include lacking buffer vegetation along the west side of the river due to the presence of VT 100B, houses, and farms, and several mass failures along the eastern valley wall. Bedrock is common on the bed in this reach, which may provide some vertical stability. M04 is in good geomorphic condition for these reasons. The reach is in fair habitat condition due to lacking large woody debris and bank and buffer vegetation on one bank. Figure 5.2. Mass failures and bedrock are common in reach M04. M04 Data Summary Reference Existing Confinement Semi Confined Semi Confined Length: 9,055 ft Stream Type B C B C Drainage Area: 141 sq. mi. Entrenchment Ratio Evolution Stage: F II Incision Ratio < Sensitivity: High Dominant Bed Material Cobble Gravel Dominant Bedform Riffle Pool Riffle Pool Major Stressors: Encroachments, channel straightening, mass failures, lacking buffer

21 Moretown, Vermont Phase 2 SGA & River Corridor Plan Page 19 M06 M06 is a 2,600 foot reach on the Mad River that begins roughly 600 feet downstream of the VT 100B bridge near Dickerson Road and ends 450 feet downstream of the Fletcher Road bridge. This short reach flows through a broad valley, but due to the presence of 100B in the middle of the valley, the phase 2 valley type is semi confined. The river for almost the entirety of this reach has been historically straightened due to the road and adjacent residential/agricultural land uses. Vegetation is lacking in the riparian buffers on both banks for most of the reach, and bank vegetation is dominated by invasive Japanese knotweed. Armoring is common along the east bank of the river, especially where it flows along 100B. Due to historic channel alterations, the river has undergone major incision in this reach, which has led to a stream type departure and loss of floodplain access. For this reason, M06 is in fair geomorphic condition. Similarly, M06 is in fair habitat condition, which is due to lacking large woody debris, poor instream cover for fish, and reduced/impacted bank and buffer vegetation. Figure 5.3. M06 flows along VT 100B and was extensively historically straightened. M06 Data Summary Reference Existing Confinement Broad Semi Confined Length: 2,603 ft Stream Type C B C Drainage Area: 131 sq. mi. Entrenchment Ratio > Evolution Stage: F III Incision Ratio < Sensitivity: Very High Dominant Bed Material Gravel Gravel Dominant Bedform Riffle Pool Riffle Pool Major Stressors: Encroachments, channel straightening, lacking buffers, bank armoring

22 Moretown, Vermont Phase 2 SGA & River Corridor Plan Page 20 M08 Reach 8 on the Mad River flows through the village of Moretown. It is approximately 1,500 feet long, beginning just above the Fletcher Road bridge downstream and ending upstream approximately 1,200 feet below the Route 100B bridge near Old Gulf Road. The river valley in this reach is naturally very broad, but Route 100B bisects it, creating a semi confined phase 2 valley. Adjacent lands to the west of the river in this reach are primarily forested, while lands to the east are primarily residential, with several homes along Route 100B, as well as the Moretown library, firehouse, and elementary school. Riparian buffer vegetation is lacking for the entirety of the reach on the eastern side of the river due to several lawns. Japanese knotweed is prevalent along both banks of the river in this reach. There is a high terrace along the east side of the river. Bedrock gorges exist both immediately upstream and downstream of this reach, which provides vertical stability to M08. Further vertical adjustments of the river bed are unlikely due to these upstream and downstream grade controls. M08 is in good geomorphic condition as a result of this stability. The reach is in fair habitat condition because it is lacking large woody debris, and bank and buffer vegetation are either lacking or dominated by invasive species. Figure 5.4. Residential land use adjacent to the river in M08 has resulted in poor riparian buffer vegetation. M08 Data Summary Reference Existing Confinement Broad Semi Confined Length: 1,492 ft Stream Type B C B C Drainage Area: 127 sq. mi. Entrenchment Ratio Evolution Stage: F I Incision Ratio < Sensitivity: Moderate Dominant Bed Material Gravel Gravel Dominant Bedform Riffle Pool Riffle Pool Major Stressors: Encroachments, channel straightening, lacking buffers, mass failure

23 Moretown, Vermont Phase 2 SGA & River Corridor Plan Page 21 M09 Reach 9 on the Mad River is just over 3,000 feet in length and was divided into two segments during the Phase 2 assessment to account for changes in valley width, channel dimensions, substrate size, and planform and slope. M09 A The downstream most segment on reach 9 is nearly 1,400 feet in length, and begins just upstream of the Moretown library and continues upstream to just above the Route 100B bridge near Old Gulf Road. The Mad River flows through a bedrock gorge in segment A, and thus a full Phase 2 assessment could not be completed on this segment. It was unsafe to walk in the river within this segment; however, limited observations and impacts were recorded from the river bank. Bedrock is abundant both on the river bed and on the banks throughout this segment, providing both vertical and horizontal control for river adjustments. There is an old mill located on the south bank of the river within this segment. It was unsafe to assess the Route 100B bridge within this segment, but it was noted as being in poor condition. Administrative judgement data were collected for the segment, placing it in good geomorphic condition. Figure 5.5. The Mad River flows through a bedrock gorge in M09 A. M09 A Data Summary *NOT ASSESSED Reference Existing Confinement Narrowly Confined Narrowly Confined Length: 1,355 ft Stream Type G C G C Drainage Area: 126 sq. mi. Entrenchment Ratio < 1.4 N/A Evolution Stage: N/A Incision Ratio < 1.2 N/A Sensitivity: N/A Dominant Bed Material Bedrock Bedrock Dominant Bedform Cascade Cascade Major Stressors: None identified

24 Moretown, Vermont Phase 2 SGA & River Corridor Plan Page 22 M09 B The upstream segment on reach M09 of the Mad River is roughly 1,800 feet in length, beginning just above the Route 100B bridge near Old Gulf Road and ending immediately upstream of the confluence of Dowsville Brook with the Mad River. The river flows through a broad valley in this segment with adjacent agricultural and residential lands. This section of the Mad River is moderately sinuous and has several large aggradational features. Additionally, the river is exhibiting planform change in this segment via a flood chute and an impending neck cutoff. There is major erosion on both banks throughout the reach, especially on the outside of meander bends. Both streambanks are blanketed in Japanese knotweed. Major historic incision has occurred in this segment, which has resulted in a loss of floodplain access and a stream type departure. The river appears to be building a juvenile floodplain at a lower elevation. Due to these adjustments, M09 B was placed in fair geomorphic condition. The morphological characteristics of the river in this segment, as well as impacted banks and buffers, led to its placement in fair habitat condition. Figure 5.6. Overly wide channel with abundant aggradation in M09 B. M09 B Data Summary Reference Existing Confinement Broad Broad Length: 1,795 ft Stream Type C F Drainage Area: 126 sq. mi. Entrenchment Ratio > Evolution Stage: F IV Incision Ratio < Sensitivity: Extreme Dominant Bed Material Gravel Gravel Dominant Bedform Riffle Pool Riffle Pool Major Stressors: Bank erosion, channel straightening, pending neck cutoff, channel encroachment, lacking buffers

25 Moretown, Vermont Phase 2 SGA & River Corridor Plan Page 23 Welder Brook Welder Brook is a tributary to the Mad River that enters the river in reach M05 near the intersection of Route 100B and Stevens Brook Road. T1.01 Reach 1 on Welder Brook was split into two segments during the Phase 2 assessment to account for changes in planform and slope, banks and buffers, valley width, grade controls, and substrate size. T1.01 A The downstream segment on reach 1 of Welder Brook begins at the confluence with the Mad River and continues upstream for roughly 2,500 feet to behind 445 Stevens Brook Road. The segment is characterized by a step pool bedform and abundant bedrock grade controls. Impacts within this segment are minimal and mostly relate to the presence of Stevens Brook Road along the north side of the stream channel. There are short sections of the brook that appear to have been straightened along the road, but for the most part, channel planform is natural. The abundant bedrock on the streambed in T1.01 A provides stability to the brook, which has not undergone incision or widening. T1.01 A is in good geomorphic condition for this stability and lack of impacts. Similarly, the segment is in good habitat condition, as it has a diversity of bed features, good instream cover, and mostly well forested buffers. Figure 5.7. Bedrock grade controls are abundant in T1.01 A. T1.01 A Data Summary Reference Existing Confinement Broad Broad Length: 2,487 ft Stream Type B B Drainage Area: 4.2 sq. mi. Entrenchment Ratio Evolution Stage: F I Incision Ratio < Sensitivity: Moderate Dominant Bed Material Cobble Cobble Dominant Bedform Step Pool Step Pool Major Stressors: Bank erosion, road encroachment, stormwater inputs, lacking buffer

26 Moretown, Vermont Phase 2 SGA & River Corridor Plan Page 24 D R AF T T1.01 B Segment B on reach one of Welder Brook is just over 1,200 feet in length and flows through a very broad valley. This segment is within a large wetland complex and the brook has a low gradient, sinuous channel. The riparian buffers are well vegetated with shrub/sapling and herbaceous vegetation. There are multiple side channels and flood chutes throughout this segment where water spreads out as flows rise. Bank erosion is common, especially on outside meander bends, as are steep riffles. The brook has not incised in this segment, and human alteration is minimal. The planform is natural and floodplain connectivity is excellent. For these reasons, T1.01 B is in good geomorphic condition. The segment is also in good habitat condition, with its abundant large woody debris, diverse bed features, and well vegetated banks and buffers. Figure 5.8. T1.01 B has a narrow, sinuous wetland channel. T1.01 B Data Summary Length: 1,242 ft Drainage Area: 4.2 sq. mi. Evolution Stage: F I Sensitivity: High Major Stressors: Confinement Stream Type Entrenchment Ratio Incision Ratio Dominant Bed Material Dominant Bedform Bank erosion Reference Existing Very Broad C > 2.2 < 1.2 Gravel Riffle Pool Very Broad C Gravel Riffle Pool

27 Moretown, Vermont Phase 2 SGA & River Corridor Plan Page 25 Doctors Brook Doctors Brook flows into the Mad River in Moretown village between the Moretown General Store and the firehouse. T2.01 Reach one on Doctors Brook begins at the confluence with the Mad River and continues upstream where it ends in the woods adjacent to Moretown Mountain Road near the Green Mountain Power substation. It was separated into two segments during the Phase 2 assessment to account for changes in channel planform and slope, channel alterations, and banks and buffers. T2.01 A The lower segment on reach one of Doctors Brook is roughly 1,200 feet in length, ending just upstream of a private bridge. The entirety of this segment appears to have been historically straightened due to the presence of houses and roads along its banks. This extensive straightening has led to major historic channel incision, a stream type departure, and a loss of floodplain access. Abundant bank armoring is preventing channel widening for much of this segment; however, areas that are not armored have severely eroding banks. Riparian buffers are lacking on both banks for most of the segment. For the aforementioned reasons, T1.01 A was placed in poor geomorphic condition. The segment is in fair habitat condition as a result of lacking large woody debris, altered channel planform, and impacted banks and buffers. Figure 5.9. T2.01 A has been extensively straightened and riprapped. T2.01 A Data Summary Reference Existing Confinement Very Broad Very Broad Length: 1,249 ft Stream Type C F Drainage Area: 4.6 sq. mi. Entrenchment Ratio > Evolution Stage: F II Incision Ratio < Sensitivity: Extreme Dominant Bed Material Cobble Cobble Dominant Bedform Riffle Pool Riffle Pool Major Stressors: Channel straightening, bank armoring, bank erosion, encroachments, lacking buffers

28 Moretown, Vermont Phase 2 SGA & River Corridor Plan Page 26 D R AF T T2.01 B The upper segment on reach one of Doctors Brook is nearly 1,400 feet in length and flows through a forested, very broad valley. The brook has a natural planform in this segment and minimal human alteration. A small section of historic channel straightening was observed at the downstream end of the segment, and another small area of channel alteration exists in the vicinity of a stream ford. Severe bank erosion was noted in this segment, especially on outside meander bends. Three mass failures were documented, the largest of which is located on the western bank of the brook toward the downstream end of the segment and is underlain by clay and sand. BCE observed one channel avulsion toward the upstream end of the segment where the brook appears to have formed a new primary flow path fairly recently. Severe historic incision was noted in this segment, which likely stems from the extensive historic channel alteration downstream in segment A. A stream type departure has occurred in T2.01 B, along with some loss of floodplain access. For these reasons, T2.01 B was placed in poor geomorphic condition. Despite channel adjustments and instability, there is abundant large woody debris and abundant pool features in this segment, as well as well forested banks and buffers. T2.01 B received a ranking of good for habitat condition. Figure Channel avulsion in T2.01 B. T2.01 B Data Summary Length: 1,372 ft Drainage Area: 4.6 sq. mi. Evolution Stage: F III Sensitivity: High Major Stressors: Confinement Stream Type Entrenchment Ratio Incision Ratio Dominant Bed Material Dominant Bedform Bank erosion, mass failures Reference Existing Very Broad C > 2.2 < 1.2 Cobble Riffle Pool Very Broad B Cobble Riffle Pool

29 Moretown, Vermont Phase 2 SGA & River Corridor Plan Page 27 Dowsville Brook Dowsville Brook is a tributary that flows into the Mad River in reach M09. The brook flows from Duxbury into Moretown, entering the Mad River near the intersection of Route 100 and Route 100B. T3.01 Reach one on Dowsville Brook begins upstream in the woods west of the cul de sac on Clark Road and ends at the confluence with the Mad River. The reach was split into three segments during assessment to account for changes in valley width, channel planform, corridor encroachments, and surrounding land uses. T3.01 A The downstream most segment on reach one of Dowsville Brook is nearly 1,400 feet in length, extending from roughly 500 feet upstream of the Route 100B bridge downstream to the confluence with the Mad River. Adjacent lands to this segment of the brook are primarily agricultural. Because of this, riparian buffer vegetation is lacking on both sides of the brook for much of the segment. The majority of T3.01 A appears to have been historically straightened due to the presence of the Route 100B crossing and surrounding agricultural lands. This historic straightening has led to channel incision, widening, and a departure from reference stream type. Due to these impacts and adjustments, T3.01 A is in fair geomorphic condition. Channel alterations and reduced bank and buffer vegetation led to the placement of T3.01 A in in fair habitat condition. Figure Straightened channel in T3.01 A. T3.01 A Data Summary Reference Existing Confinement Very Broad Very Broad Length: 1,383 ft Stream Type D C Drainage Area: 9.1 sq. mi. Entrenchment Ratio > Evolution Stage: F III Incision Ratio < Sensitivity: Very High Dominant Bed Material Gravel Gravel Dominant Bedform Riffle Pool Riffle Pool Major Stressors: Channel straightening, bank erosion, bank armoring, lacking buffers

30 Moretown, Vermont Phase 2 SGA & River Corridor Plan Page 28 D R AF T T3.01 B Segment B on reach one of Dowsville Brook is nearly 3,600 feet in length, beginning about 500 feet above the Route 100B bridge and ending upstream about 500 feet below the Route 100 bridge. The brook flows through forested land in this segment and has minimal channel alteration. T3.01 B has undergone major aggradation and channel widening, leading to planform change. The channel is braided at low flows at some locations in this segment, but there are side channels and flood chutes throughout the segment, creating braiding at higher flows as well. Bank erosion is common on the outside of meander bends. Debris jams are abundant and are also contributing to planform change within T3.01 B. This segment is in fair geomorphic condition due to the major adjustments it is undergoing. The brook has abundant large woody debris and pools, as well as well forested banks and buffers. T3.01 B is in good habitat condition. Figure Aggradation and low flow braiding in T3.01 B. T3.01 B Data Summary Length: 3,557 ft Drainage Area: 9.1 sq. mi. Evolution Stage: DIId Sensitivity: Extreme Major Stressors: Confinement Stream Type Entrenchment Ratio Incision Ratio Dominant Bed Material Dominant Bedform Bank erosion, mass failure Reference Existing Very Broad D > 2.2 < 1.2 Gravel Riffle Pool Very Broad D Gravel Riffle Pool

31 Moretown, Vermont Phase 2 SGA & River Corridor Plan Page 29 D R AF T T3.01 C The upstream most segment on reach one of Dowsville Brook is characterized as having a higher slope than the downstream segments. This nearly 2,500 foot segment flows through forested and residential land from just downstream of the Route 100 bridge upstream to near the cul de sac on Clark Road in Duxbury. Historic and recent channel alterations were observed during the Phase 2 assessment, including channel straightening, dredging, windrowing, and berms. The uppermost portion of this segment has a higher slope than the rest of the segment, which is flatter and has large depositional features. Large flood chutes are present throughout the segment, contributing to planform adjustment. Sections of the brook appear to have been historically straightened behind several of the homes on Clark Road. Historic and recent berms, windrowing, and dredging were observed in the lower half of the segment above the Route 100 bridge. Major incision has occurred in this segment, though it has not led to a stream type departure. T3.01 C is in fair geomorphic condition and fair habitat condition due to the aforementioned alterations and adjustments, as well as impacted riparian buffers. Figure T3.01 C at cross section location. T3.01 C Data Summary Length: 2,476 ft Drainage Area: 9.1 sq. mi. Evolution Stage: F III Sensitivity: Very High Major Stressors: Confinement Stream Type Entrenchment Ratio Incision Ratio Dominant Bed Material Dominant Bedform Reference Existing Very Broad Cb > 2.2 < 1.2 Gravel Riffle Pool Very Broad Cb Gravel Riffle Pool Channel straightening, windrowing, encroachments, development, bank erosion, dredging

32 Moretown, Vermont Phase 2 SGA & River Corridor Plan Page 30 Jones Brook Jones Brook is a tributary to the Winooski River that flows through the towns of Moretown and Berlin. Three reaches on Jones Brook were included in this Phase 2 assessment. R16.S2.01 Reach one on Jones Brook flows adjacent to agricultural lands near the confluence with the Winooski River. The reach was split into three segments during the assessment to account for changes in valley width, channel planform and slope, and depositional features. R16.S2.01 A The downstream most segment on reach one of Jones Brook is approximately 2,300 feet in length, beginning roughly 700 feet above the Three Mile Bridge Road bridge and ending at the confluence with the Winooski River. R16.S2.01 A flows through a very broad valley along several corn fields. Most of the segment appears to have been historically straightened due to the surrounding land use. Historic incision occurred within this segment and channel widening is actively occurring. Riprap is abundant along both banks, but bank erosion is occurring where riprap is not present. Some planform change was noted in the form of flood chutes. Lateral adjustments are being limited by bank armoring. R16.S2.01 A is in fair geomorphic condition for these reasons. The brook is also in fair habitat condition in this segment due to its altered planform, as well as lacking bank and buffer vegetation. Japanese knotweed is prevalent along both banks. Figure Large bar and riprapped bank in R16.S2.01 A. R16.S2.01 A Data Summary Reference Existing Confinement Very Broad Very Broad Length: 2,313 ft Stream Type C C Drainage Area: 10.1 sq.mi. Entrenchment Ratio > Evolution Stage: F III Incision Ratio < Sensitivity: Very High Dominant Bed Material Gravel Gravel Dominant Bedform Riffle Pool Riffle Pool Major Stressors: Channel straightening, bank armoring, bank erosion, lacking buffers

33 Moretown, Vermont Phase 2 SGA & River Corridor Plan Page 31 D R AF T R16.S2.01 B Segment B on reach one of Jones Brook is roughly 1,200 feet in length. This segment differs from segments A and C primarily in channel planform and dimensions. R16.S2.01 B is characterized by abundant large depositional features, creating an extremely wide channel and low flow braiding conditions. There are several flood chutes and side channels that appear to be wetted at various flow conditions (including low flow). There are few human impacts to the brook within this segment, which include one stream ford and a very short section of minor windrowing just upstream of the ford. There is a major gully coming off of the east valley wall within this segment that may contribute large amounts of fine sediment to the brook. The brook is part of a naturally very dynamic system. R16.S2.01 B is in fair geomorphic condition as a result of its abundant adjustments. Similarly, the book is in fair habitat condition within this segment due to lacking instream cover and its hydrologic conditions that create a shallow channel without a diversity of bed features. Figure There is major aggradation and braiding in R16.S2.01 B. R16.S2.01 B Data Summary Length: 1,230 ft Drainage Area: 10.1 sq.mi. Evolution Stage: D IId Sensitivity: Extreme Major Stressors: Confinement Stream Type Entrenchment Ratio Incision Ratio Dominant Bed Material Dominant Bedform Bank erosion, gully Reference Existing Very Broad D > 2.2 < 1.2 Gravel Braided Very Broad D Gravel Braided

34 Moretown, Vermont Phase 2 SGA & River Corridor Plan Page 32 D R AF T R16.S2.01 C The upstream most segment on reach one of Jones Brook is just over 900 feet in length and flows through a narrower, steeper valley than the two downstream segments. The brook is characterized by a naturally straight channel with large substrate. The brook has undergone historic incision and recent channel widening. Large bars are present at the downstream end of the segment. It appears that the brook has been minimally altered, as it flows through the woods away from development along Jones Brook Road. R16.S2.01 C is in fair geomorphic condition as a result of historic and recent channel adjustments. The brook is also in fair habitat condition for many reasons, including lacking pool features, unstable banks, and a wide channel with mostly shallow water. Figure Wide, straight channel in R16.S2.01 C. R16.S2.01 C Data Summary Length: 945 ft Drainage Area: 10.1 sq.mi. Evolution Stage: F III Sensitivity: High Major Stressors: Confinement Stream Type Entrenchment Ratio Incision Ratio Dominant Bed Material Dominant Bedform Bank erosion, mass failures Reference Existing Broad C > 2.2 < 1.2 Gravel Riffle Pool Broad BC Gravel Riffle Pool

35 Moretown, Vermont Phase 2 SGA & River Corridor Plan Page 33 R16.S2.02 Reach two on Jones Brook begins upstream at the confluence with Kelley Brook and ends downstream near 592 Jones Brook Road. The reach was divided into five segments during the assessment to account for changes in valley width and bank/buffer vegetation. R16.S2.02 A The downstream most segment on reach two of Jones Brook flows through a narrow valley. The downstream half of the segment flows through the woods, while the upstream half flows through a residential area along the west bank of the brook. Aggradation is a major process that is currently occurring within R16.S2.02 A. Numerous large bars are present throughout the segment causing the formation of steep riffles and channel widening. Although moderate historic incision has occurred within this segment, floodplain access is still mostly intact. Riparian buffers are lacking in the vicinity of two houses along the western bank of Jones Brook. Bank erosion is common along both banks within this segment, which provides further evidence that channel widening is occurring, and four mass failures are present. R16.S2.02 A is in fair geomorphic condition as a result of historic and active channel adjustments. This segment is also in fair habitat condition due to such factors as lacking instream cover, reduced bank and buffer vegetation, and lacking pool features. Figure Aggradation is a major process currently occurring within R16.S2.02 A. R16.S2.02 A Data Summary Reference Existing Confinement Narrow Narrow Length: 2,509 ft Stream Type C C Drainage Area: 9.5 sq. mi. Entrenchment Ratio > Evolution Stage: F III Incision Ratio < Sensitivity: Very High Dominant Bed Material Gravel Gravel Dominant Bedform Riffle Pool Riffle Pool Major Stressors: Bank erosion, mass failures, lacking buffers, gully

36 Moretown, Vermont Phase 2 SGA & River Corridor Plan Page 34 D R AF T R16.S2.02 B Segment B on reach two of Jones Brook is a short segment only roughly 900 feet in length. The brook flows through a slightly wider valley in this segment than downstream and has more channel alteration due to the presence of residences on both sides of the brook. Much of the segment appears to have been historically straightened up against the eastern valley wall due to residential land use on the west. Buffer vegetation is lacking for most of the segment on the western side of the brook, but also for a small section on the eastern side. The historic straightening in this segment appears to have led to major historic incision, resulting in a stream type departure and loss of floodplain access. Major aggradation has also occurred within this segment, as evidenced by several large bar features. For these reasons, R16.S2.02 B is in fair geomorphic condition. The segment is also in fair habitat condition as a result of lacking instream cover and pool habitat, channel adjustments that have created a wide, shallow channel, and lacking bank and buffer vegetation. Figure Wide, depositional channel in R16.S2.02 B. R16.S2.02 B Data Summary Length: 880 ft Drainage Area: 9.5 sq. mi. Evolution Stage: F III Sensitivity: Very High Major Stressors: Confinement Stream Type Entrenchment Ratio Incision Ratio Dominant Bed Material Dominant Bedform Reference Existing Broad C > 2.2 < 1.2 Gravel Riffle Pool Broad BC Gravel Riffle Pool Channel straightening, bank erosion, encroachments, lacking buffer, dredging

37 Moretown, Vermont Phase 2 SGA & River Corridor Plan Page 35 D R AF T R16.S2.02 C Segment C on reach two of Jones Brook flows through a narrower valley than the adjacent segments. It is roughly 1,200 feet in length and flows mostly through the woods along Jones Brook Road. Very few channel alterations were observed within this segment, which has a mostly natural planform. Moderate historic incision was noted at the cross section for R16. S2.02 C, as well as minor widening. A few areas of bank erosion were noted in this segment, particularly on the eastern bank. Due to historic and recent channel adjustments, this segment was placed in fair geomorphic condition. R16.S2.02 C lacked large woody debris at the time of the assessment. Hydrologic characteristics and impacted bank and buffer vegetation on one side of the channel also contributed to the segment being placed in fair habitat condition. Figure R16.S2.02 C has a narrower valley and is naturally more entrenched than downstream segments. R16.S2.02 C Data Summary Length: 1,240 ft Drainage Area: 9.5 sq. mi. Evolution Stage: F III Sensitivity: High Major Stressors: Confinement Stream Type Entrenchment Ratio Incision Ratio Dominant Bed Material Dominant Bedform Bank erosion, lacking buffer Reference Existing Semi Confined BC < 1.2 Cobble Riffle Pool Semi Confined BC Cobble Riffle Pool

38 Moretown, Vermont Phase 2 SGA & River Corridor Plan Page 36 D R AF T R16.S2.02 D Segment D on R16.S2.02 is very short, only 584 feet in length. This segment flows through the woods and has a large bedrock grade control at its downstream end. This grade control provides vertical stability to the channel within R16.S2.02 D, which has prevented major channel incision. Jones Brook upstream of the bedrock grade control appears to be undergoing minor channel widening with extensive bank erosion along the west bank. Overall, R16.S2.02 D was reported to be in good geomorphic condition due to only minor channel adjustments. Similarly, segment D was placed in good habitat condition, as it has good instream cover, a diversity of bed features, and mostly well vegetated banks and buffers. Figure Large bedrock grade control at the downstream end of R16.S2.02 D. R16.S2.02 D Data Summary Length: 584 ft Drainage Area: 9.5 sq. mi. Evolution Stage: F III Sensitivity: Moderate Major Stressors: Confinement Stream Type Entrenchment Ratio Incision Ratio Dominant Bed Material Dominant Bedform Bank erosion, gully Reference Existing Semi Confined C > 2.2 < 1.2 Gravel Riffle Pool Semi Confined C Cobble Riffle Pool

39 Moretown, Vermont Phase 2 SGA & River Corridor Plan Page 37 D R AF T R16S2.02 E The upstream most segment on reach two of Jones Brook is nearly 700 feet in length, and flows through primarily residential land along Jones Brook Road. This land use appears to have resulted in historic straightening for the entirety of this segment. Severe historic incision has occurred within R16.S2.02 E, causing a stream type departure and loss of floodplain access. Some channel widening is occurring, though it is limited in some locations due to riprap. Riparian buffer vegetation is lacking along the western side of Jones Brook for the whole segment. R16.S2.02 E is in fair geomorphic condition due to extensive historic channel alteration and severe historic incision. Large woody debris, bed features, and bank and buffer vegetation are lacking, which resulted in the placement of the segment in fair habitat condition. Figure Jones Brook has a straight and severely incised channel in R16.S2.02 E. R16.S2.02 E Data Summary Length: 695 ft Drainage Area: 9.5 sq. mi. Evolution Stage: F III Sensitivity: Extreme Major Stressors: Confinement Stream Type Entrenchment Ratio Incision Ratio Dominant Bed Material Dominant Bedform Reference Existing Broad C > 2.2 < 1.2 Gravel Riffle Pool Broad F Cobble Riffle Pool Channel straightening, encroachment, bank erosion, bank armoring, lacking buffer

40 Moretown, Vermont Phase 2 SGA & River Corridor Plan Page 38 R16.S2.03 Reach three on Jones Brook spans the area between the confluence of Kelley Brook and the confluence of Herring Brook. This reach was divided into three segments during the assessment to account for changes in corridor encroachment and channel planform. Jones Brook flows along Jones Brook Road and development along the road for all of reach three. R16.S2.03 A The downstream most segment on reach three of Jones Brook is just over 800 feet in length, beginning at the confluence with Kelley Brook downstream and ending upstream where the brook flows away from Jones Brook Road. This segment has a very broad valley by reference; however, the valley is bisected by Jones Brook Road, which functionally narrows the valley. All of segment A appears to have been historically straightened due to the placement of Jones Brook Road in the western corridor and a house on the east of the brook. Despite this historic straightening, minimal channel incision has occurred within R16.S2.03 A. Similarly, aggradation, widening, and planform change are minimal in this segment. A geomorphic condition of good was given to this segment for this lack of channel adjustments and the segment s relative stability. R16.S2.03 A ranked fair for habitat condition for the brook s lack of large woody debris, its altered planform, and lacking bank and buffer vegetation. Figure R16.S2.02 A looking downstream at the cross section location. R16.S2.03 A Data Summary Reference Existing Confinement Very Broad Narrow Length: 804 ft Stream Type C C Drainage Area: 6.5 sq. mi. Entrenchment Ratio > Evolution Stage: F II Incision Ratio < Sensitivity: High Dominant Bed Material Gravel Gravel Dominant Bedform Riffle Pool Riffle Pool Major Stressors: Channel straightening, encroachment, lacking buffers, bank erosion

41 Moretown, Vermont Phase 2 SGA & River Corridor Plan Page 39 D R AF T R16.S2.03 B The second segment on reach three of Jones Brook is characterized by major channel encroachment by Jones Brook Road. This very short segment (just over 400 feet in length) flows directly along the road. The brook has been straightened along the eastern valley wall for nearly the entire segment and is currently trapped between the road and valley wall. There is a major human caused change in valley width in this segment due to the presence of Jones Brook Road. Extensive bank armoring is present along the road. The road encroachment creates a human elevated floodplain and a high incision ratio, and has resulted in loss of floodplain access and a stream type departure. Lateral channel adjustments are being prevented by the bank armoring present on the west side of the channel and the valley wall immediately on the east. R16.S2.03 B is in fair geomorphic condition for these reasons. The straightened channel in this segment lacks large woody debris, pool features, and bank and buffer vegetation on one side. For these reasons, R16.S2.03 B is also in fair habitat condition. Figure R16.S2.03 B has been extensively straightened along Jones Brook Road. R16.S2.03 B Data Summary Length: 416 ft Drainage Area: 6.5 sq. mi. Evolution Stage: F III Sensitivity: Very High Major Stressors: Confinement Stream Type Entrenchment Ratio Incision Ratio Dominant Bed Material Dominant Bedform Reference Existing Very Broad C > 2.2 < 1.2 Gravel Riffle Pool Semi Confined F Gravel Riffle Pool Channel straightening, encroachment, lacking buffer, bank armoring

42 Moretown, Vermont Phase 2 SGA & River Corridor Plan Page 40 D R AF T R16.S2.03 C The upstream most segment on reach three of Jones Brook is the longest, at 2,100 feet. Jones Brook appears to have been historically straightened for the entire length of this segment due to several houses along Jones Brook Road. Five ledge grade controls are present in the middle and at the downstream end of this segment, which afford the channel some vertical stability. Moderate historic incision has occurred within R16.S2.03 C likely as a result of channel alteration. Widening is currently occurring as evidenced through abundant bank erosion. Riparian buffer vegetation is lacking for about half of the segment. R16.S2.03 C is in fair geomorphic condition and fair habitat condition. Figure Straight channel in R16.S2.03 C. R16.S2.03 C Data Summary Length: 2,099 ft Drainage Area: 6.5 sq. mi. Evolution Stage: F III Sensitivity: Very High Major Stressors: Confinement Stream Type Entrenchment Ratio Incision Ratio Dominant Bed Material Dominant Bedform Reference Existing Very Broad C > 2.2 < 1.2 Gravel Riffle Pool Broad C Gravel Riffle Pool Channel straightening, encroachment, lacking buffers, bank erosion

43 Moretown, Vermont Phase 2 SGA & River Corridor Plan Page 41 Kelley Brook Kelley Brook is a tributary to Jones Brook that flows from west to east in Moretown and enters Jones Brook in reach R16.S2.02. R16.S2.02 S1.01 Reach one on Kelley Brook was split into two segments during assessment due to changes in channel dimensions, corridor encroachments, and valley width. R16.S2.02 S1.01 A The downstream segment on reach one of Kelley Brook is characterized by a broad valley and moderate channel slope. Bedrock grade controls are common throughout this segment. Ward Brook Road is a corridor encroachment for nearly the entire length of the segment. Almost all of R16.S2.02 S1.01 A has been historically straightened due to the placement of Ward Brook Road and houses along it. Additionally, there is extensive bank armoring, especially in areas where the brook is directly adjacent to the road. Channel straightening and bank armoring have led the brook to undergo major historic incision in this segment, resulting in a loss of floodplain access and a stream type departure. Channel widening is prevented by bank armoring on one side of the channel and the location of the valley wall on the other side for much of the segment; however, bank erosion is common where armoring is not present. Segment A was placed in fair geomorphic condition for these reasons. Habitat condition is also fair due to the altered channel planform, as well as lacking large woody debris, pool features, and bank and buffer vegetation. Figure R16.S2.02 S1.01 A flows directly along Ward Brook Road for much of the segment. R16.S2.02 S1.01 A Data Summary Length: 3,425ft Drainage Area: 2.1 sq. mi. Evolution Stage: F II Sensitivity: Very High Major Stressors: Reference Existing Confinement Broad Broad Stream Type C b G Entrenchment Ratio > Incision Ratio < Dominant Bed Material Cobble Cobble Dominant Bedform Riffle Pool Riffle Pool Channel straightening, encroachment, lacking buffers, bank armoring, stormwater inputs

44 Moretown, Vermont Phase 2 SGA & River Corridor Plan Page 42 D R AF T R16.S2.02 S1.01 B The upstream segment on reach one of Kelley Brook is similar to segment A but has a narrower valley and is less incised. This segment is just over 3,600 feet in length beginning downstream about 1,400 feet above the culvert at 360 Ward Brook Road and ending upstream near 1309 Ward Brook Road. More than half of this segment has been historically straightened due to the placement of Ward Brook Road and houses along it. Bank armoring and lacking buffers are common along this stretch of the brook, especially where it flows adjacent to the road. Bedrock grade controls are abundant within this segment (fifteen in total), which offer the brook vertical stability. Despite extensive straightening, R16.S2.02 S1.01 B has overall not undergone incision, likely due to the abundance of bedrock grade controls. The segment scored reference for geomorphic condition as a result of its lack of adjustments. R16.S2.02 S1.01 B is in good habitat condition and has a diversity of bed features including large woody debris and pools. Figure Bedrock grade controls are abundant in this segment. R16.S2.02 S1.01 B Data Summary Length: 3,611ft Drainage Area: 2.1 sq. mi. Evolution Stage: F I Sensitivity: Moderate Major Stressors: Confinement Stream Type Entrenchment Ratio Incision Ratio Dominant Bed Material Dominant Bedform Reference Existing Broad Cb > 2.2 < 1.2 Cobble Riffle Pool Narrow Cb Cobble Riffle Pool Channel straightening, encroachment, lacking buffers, bank armoring, stormwater inputs

45 Moretown, Vermont Phase 2 SGA & River Corridor Plan Page 43 Herring Brook Herring Brook is a tributary to Jones Brook that flows west to east and enters Jones Brook at the upstream end of reach R16.S2.03. R16.S2.03 S1.01 Reach one on Herring Brook is located adjacent to Herring Brook Road between the confluence with Jones Brook downstream and just below Herring Lynch Trail upstream. The reach was divided into three segments during the assessment to account for changes in valley width and banks and buffers. R16.S2.03 S1.01 A Segment A is the downstream most segment on reach one of Herring Brook. The segment begins at the confluence with Jones Brook and extends upstream for just over 800 feet to where the brook enters the woods. This segment is characterized by extensive historic channel straightening due to the presence of a house and Jones Brook Road within the river valley. This channel straightening has led to major historic incision. Bank armoring is also extensive in R16.S2.03 S1.01 A and is preventing the channel from widening, creating a deep and narrow channel. A stream type departure has occurred in segment A due to the historic incision and boundary conditions preventing channel evolution. R16.S2.03 S1.01 A is in fair geomorphic condition for the aforementioned reasons. Similarly, this segment is in fair habitat condition due to a lack of bed features caused by extensive straightening, lacking large woody debris, altered channel planform, and poorly vegetated banks and buffers. R16.S2.03 S1.01 A Data Summary Length: 832 ft Drainage Area: 4.4 sq. mi. Evolution Stage: F II Sensitivity: High Major Stressors: Figure Extensive riprap and straightening in R16.S2.03 S1.01 A. Reference Existing Confinement Very Broad Very Broad Stream Type C E Entrenchment Ratio > Incision Ratio < Dominant Bed Material Gravel Cobble Dominant Bedform Riffle Pool Riffle Pool Channel straightening, bank armoring, lacking buffers

46 Moretown, Vermont Phase 2 SGA & River Corridor Plan Page 44 D R AF T R16.S2.03 S1.01 B The second segment on reach one of Herring Brook flows primarily through the woods adjacent to Herring Brook Road. The segment begins at the edge of the woods downstream and continues upstream for just over 1,700 feet to where the valley narrows between 423 and 493 Herring Brook Road. R16.S2.03 S1.01 B appears to have undergone some historic channel straightening in the upper portion of the segment. Incision is currently occurring within this segment as evidenced through the presence of one headcut near the upstream end of the segment. This incision has led to a loss of floodplain access and stream type departure in most of the segment. Channel widening is also an active process in this segment; bank erosion is common, particularly in the upper part of the segment. R16.S2.03 S1.01 B is in fair geomorphic condition for these reasons. Although the stream channel is actively adjusting in this segment, there is abundant large woody debris, instream cover, and pool habitat, and the banks and buffers are generally well forested. These factors led to the placement of this segment in good habitat condition. Figure Headcut in R16.S2.03 S1.01 B. R16.S2.03 S1.01 B Data Summary Length: 1,725 ft Drainage Area: 4.4 sq. mi. Evolution Stage: F II Sensitivity: Very High Major Stressors: Confinement Stream Type Entrenchment Ratio Incision Ratio Dominant Bed Material Dominant Bedform Reference Existing Broad C > 2.2 < 1.2 Gravel Riffle Pool Broad F Gravel Riffle Pool Channel straightening, bank erosion, lacking buffers, headcut

47 Moretown, Vermont Phase 2 SGA & River Corridor Plan Page 45 D R AF T R16.S2.03 S1.01 C The upstream most segment on reach one of Herring Brook is roughly 2,400 feet in length and flows through a broad valley. Sections of the brook flow directly along Herring Brook Road and/or houses along the road and were likely historically straightened, while other sections flow through the woods and have minimal human impacts. Very minor incision was observed at the cross section for this segment, and scattered minor bank erosion indicates that widening may be occurring in some sections of this segment. Riparian buffers are lacking in this segment, particularly on the northern side of the channel where infrastructure is common. Overall, major adjustment is not occurring within this segment and, for this reason, it was placed in good geomorphic condition. R16.S2.03 S1.01 C is also in good habitat condition with its ample large woody debris, nice pools, good floodplain connectivity, and mostly well forested banks and buffers. Figure Downstream view at cross section in R16.S2.03 S1.01 C. R16.S2.03 S1.01 C Data Summary Length: 2,368 ft Drainage Area: 4.4 sq. mi. Evolution Stage: F I Sensitivity: High Major Stressors: Confinement Stream Type Entrenchment Ratio Incision Ratio Dominant Bed Material Dominant Bedform Reference Existing Broad C > 2.2 < 1.2 Gravel Riffle Pool Broad C Cobble Riffle Pool Bank erosion, lacking buffers, bank armoring, channel straightening